Bernard Jenkin is the Member of Parliament for Harwich and North Essex and Chairman of the Public Administration Select Committee. Bernard was the architect of “North East Says No” and also helped to set up and guide “No2AV”. Follow Bernard on Twitter.

Tim Montgomerie is one of the most creative Conservative thinkers of our generation, but it would be unfair to insist that his ideas should achieve a 100 per cent hit rate. His suggestion that a referendum on the EU could be held on the same day as the next general election, to boost the turnout of Conservative voters and potentially to reduce the number of voters defecting to UKIP, sounds like a brilliant wheeze for us, but this would be dangerous in practice, and wrong in principle. This is poisoning the well of direct democracy, not advancing it.

We politicians may use elections to gain power, but that is not their main purpose. Their purpose is to provide for democratic consent. Equally, it may be tempting to use referendums to help us get power, but that both destroys the moral case for demanding this special and unique form of democratic consent, and could fatally undermine the legitimacy and authority of the result. Elections are subject to strict rules and procedures so they are fair, so that they serve to allow the people to choose their representatives. Referendums need to be subject to similar rules. A referendum should be an opportunity for the electorate to determine a major constitutional issue, which is best resolved independently of party politics and of who holds power. For a government arbitrarily to use the process of a referendum to deliberately manipulate the result of an election, or vice versa, sets dangerous precedents, which we would live to regret.

Just last year, Alex Salmond advocated that the referendum on whether Scotland should leave the UK should be held on the same day as the Scottish Parliament elections or the general election. Why did he suggest this? He told Canada’s Globe and Mail last year: “so that the opposition parties would have the tactics of their ‘No’ campaigns tied up with their fates in the legislative election”. The government would be right to deny him this opportunity to manipulate the elections. It is plainly wrong to try to use a referendum to influence a general election result, as it is to use an election to sway a referendum result.

In a referendum, voters are not choosing a government, but deciding an issue. For a short spell, there is the refreshing spectacle of politicians addressing an issue, rather than jockeying for position. Parties are eclipsed by cross-party, and extra-parliamentary campaigns. It is particularly important that this should be able to happen, when a great issue, like the EU, divides the main parties. In these ways, the issue at stake becomes the focus of debate, not party politics. For once, the broadcasters primary duty must be to balance their coverage of the issue, rather than of the parties, balancing protagonists for the “yes” and “no” campaigns, instead of allowing party HQs to dictate who is heard. Our experience of referendums in the UK is that these debates matter. The North East referendum debates swung voters violently away from initial polls in favour of regional assemblies. The same happened with AV.

At the time of the North East referendum, the Electoral Commission was implacably opposed to running elections with referendums. In February 2002, the then BBC chief political adviser expressed a view about this, when there was a threat that a referendum on the Euro would be held at the same time as other elections. She had met Helen Liddell, the then-Secretary of State for Scotland, and Jack McConnell, the then-First Minister, and she had

"made my views very clear to the politicians and the BBC…it was a bad move…condescending to Scotland, Wales and Northern Ireland…it would put broadcasters in an impossible position".

They never explained why they changed their minds for the AV referendum. The LibDems wanted that, because they were worried their local elections vote share would collapse if it was not held on the same day. We are fortunate the AV debates utterly overshadowed the local elections, and that the AV result was decisive, but this set the UK on a constitutional slippery slope.

The clear “yes-no” debate on the EU would be blurred by combining an EU referendum with a general election, driving the referendum debate back into political ghetto of the Westminster based political parties. Broadcasters would be forced to allow the EU debate to be filtered and obscured by the party battle for control of Downing Street, as they struggled to give balance to the concurrent party battle. Informing the voter would become harder. The quality of debate would be eroded. There would be cries of unfairness. A close result would lack decisive authority.

And be careful what you wish for, Tim. What would be the question in your referendum? Would our party be united around the “yes” or “no” campaign, or would we be placing our party exactly where Alex Salmond wants to put his election and referendum opponents? The question of “who governs?”, and the question of Europe, are both too important to the future of the British people to make them suffer the obscuring effects of the wanton manipulation of the likes advocated by Alex Salmond.

Tim recognises that a referendum on the same date as the next general election would be seen as a tactic to influence the election result rather than putting an honest question to the people. It is hard to see the legislation for such a referendum making it through Parliament. Tim suggests “the referendum might be approved if passage was tied to something else that Nick Clegg's party really wanted”. This would make the proposal even less principled and possibly more dangerous. What would he demand?

Attlee denounced the referendum as “a device of demagogues and dictators”, a view echoed word-for-word by Margaret Thatcher (though she later voted for one on Maastricht). That view reflected their wartime experience of the way Hitler had ruthlessly used referendums to advance his own cause, and predated the extraordinary facility for direct communication we enjoy today. Many of us have championed the cause of a referendum on our EU membership. We should not tarnish that cause by laying ourselves open to that charge, or risk poisoning the debate with less noble motives.